A conventional way for packing an article with a cushioning agent mostly is wrapping around the article with a plastic sheet on which a plurality of small raised air bags are projected to attain to the shock-absorbed cushioning functions. But the shock absorption capability of the small air bags is limited such that the cushioning and the shock absorption effects to a larger shock or impulse cannot be attained. Therefore, an air packing bag is developed to take as a wrapping cushioning means.
However, the air bag made from polyethylene (PE) is easy to be pierced through by a sharp acute angle of a packed article or an adjoining angle of hardware; once a small broken hole appears on the air packing bag, fluid in the air packing bag is then leaked out. Please refer to The U.S. Pat. No. 4,850,912 entitled as “Container for sealingly containing a fluid”, The U.S. Pat. No. 5,261,466 entitled as “Process for continuously filling fluid into a plurality of closed bags”, The U.S. Pat. No. 5,427,830 entitled as “Continuous, inflatable plastic wrapping material” and Japan utility model patent publishing No. H5-95851 entitled “Seal bag for fluids”. Each air cylinder of each air packing bag disclosed thereby is disposed with an independent check valve; when parts of air cylinders are broken, only air in the broken air cylinders is leaked out and air in other unbroken air cylinders is not caused to leak out. Although this kind of structure allows entire air not to be leaked out when the parts of air cylinders are broken, but broken parts of the air cylinders will cause the cushioning protection function to be lost to cause a packed article to be damaged or scratched easily.